Understanding pesticide pollution: sources, classification, environmental and health impacts, analytical approaches, and treatment techniques with special emphasis on India.

Pesticide contamination in water has become a significant environmental and public health issue, intensified by the widespread and uncontrolled use of pesticides for agricultural and non-agricultural purposes. This paper reviews various types of pesticides, including insecticides, herbicides, and fungicides each with their distinct chemical properties. It also focuses on the primary sources and pathways of pesticide contamination, such as surface runoff, pesticide production plants, wastewater treatment plant, and atmospheric deposition, emphasizes the need for effective monitoring and management strategies. Furthermore, this review discusses analytical techniques used to accurately detect and quantify pesticide residues, including gas chromatography-mass spectrometry, electron capture detection, nitrogen-phosphorus detector, flame ionization detector, liquid chromatography-mass spectrometry, and high-performance liquid chromatography. Additionally, it analyses the recent trends in pesticide consumption in India, indicating the increase in pesticide use across various agricultural sectors. It also reviews several conventional and advanced treatment technologies for pesticide removal, including physical methods (e.g., adsorption, membrane filtration), chemical methods (e.g., electrochemical treatment, advanced oxidation processes), and various biological techniques (e.g. bioremediation, constructed wetlands). The effectiveness of these methods depends on factors such as pesticide type, concentration, environmental conditions, and compliance with permissible limits. The review concludes that future research should focus on optimizing treatment methods; integrating biological, physical, and chemical approaches; and expanding their applicability to a wider range of pesticide compounds. An interdisciplinary approach in developing solutions for simultaneous detection and treatment is essential and should be strongly emphasized.